Selection principle Security: 1, corrosive medium: it is appropriate to use plastic King solenoid valve and all stainless steel; for strong corrosion of the medium must be selected isolation diaphragm type. Neutral medium, also should use copper alloy as the valve shell material of the solenoid valve, otherwise, the valve shell often rust off, especially the action is not frequent occasions. Ammonia valve can not be used with copper.

2, explosive environment: must choose the appropriate explosion-proof grade products, open-air installation or dust and more occasions should use waterproof, dust varieties.

3, solenoid valve nominal pressure should exceed the maximum working pressure in the tube.

Applicability: 1, dielectric properties

1) gas, liquid or mixed state, respectively, the use of different varieties of solenoid valve;

2) medium temperature of different specifications of products, or the coil will burn, seal aging, serious impact on life expectancy;

3) medium viscosity, usually below 50cSt. If more than this value, with a diameter greater than 15mm, with the multi-function solenoid valve, with a diameter less than 15mm, with a high viscosity solenoid valve.

Medium cleanliness is not high, should be equipped with electromagnetic valve before the recoil filter valve, low pressure, the choice of direct acting diaphragm solenoid valve;

5) if the directional flow of media, and does not allow the flow back, with two-way flow;

6) medium temperature should be chosen within the allowable range of electromagnetic valve.

2, pipeline parameters

1) according to the media flow requirements and pipe connection method to select the valve port and model;

2) according to the flow and valve Kv value of the selected nominal diameter, also optional with the diameter of the pipe;

3 working pressure: minimum working pressure in the 0.04Mpa above is optional indirect pilot type; minimum working pressure is close to or less than zero must be selected direct or step by step direct type.

3, environmental conditions

1) the maximum and minimum temperature should be selected within the allowable range;

2) in the environment of high relative humidity and a drop of rain and so on, should be selected water solenoid valve;

3) environment often vibration, bumps and shocks should choose special varieties of occasions, such as marine solenoid valve;

4) the use of corrosive or explosive environment should be given priority to the use of the safety requirements of the selection of corrosion resistant type;

5) if the environmental space is limited, it is necessary to use the multi-function solenoid valve, because it eliminates the bypass and three manual valves and easy online maintenance.

4, the power supply conditions

1) according to the types of power supply, the use of AC and DC solenoid valve. In general, easy to use AC power;

2) voltage specifications with the priority to use AC220V.DC24V;

3) the power supply voltage fluctuation usually selects +%10%.-15%, the direct current permits the%10 or so, if the ultra difference, must take the voltage stabilizing measure;

4) the rated current and power consumption should be selected according to the power supply. Must pay attention to the high value of VA, when the capacity is insufficient, should give priority to the use of indirect electromagnetic valve.

5 control accuracy

1) ordinary solenoid valve is only open and close the two positions, in the control of high precision and parameters of the requirements of a stable need to use a number of solenoid valve;

2) the action time: the electrical signal is switched on or cut off to the main valve action completion time;

3) leakage: the value given by the sample is a common economic scale.

Reliability: 1, working life, this is not included in the factory test project, is a type of test items. In order to ensure the quality of the formal election of the brand manufacturers.

2, the work of the system: a long-term work system, repeated short-term work system and short-term work system three. For a long time the opening of the valve is only a short time to close the case, it is appropriate to use normally open solenoid valve.

3, the operating frequency: high frequency of action, the structure should be optimized direct acting solenoid valve, the power to listen to the preferred exchange.

4, action reliability

Strictly speaking, this test has not yet formally included in the solenoid valve professional standards, to ensure that the quality should be regular elections manufacturers of brand-name products. Number of occasions, some not much action, but has very high reliability requirements, such as fire protection, emergency protection, cut can not be taken lightly. Particularly important, should also take two used for double insurance.

Economy: It chooses one of the scales, but it must be based on security, applicable and reliable.

Economy is not only the price of the product, but also to give priority to its function and quality, as well as the cost of installation and maintenance and other accessories.

More importantly, a solenoid valve in the entire automatic control system in the entire automatic control system and even the production line of the cost is minimal, if the temptation is small and cheap and the resulting damage to the group is a huge damage.